Answer in brief
CVE-2026-23247 records a Medium severity (CVSS 5.5) vulnerability in tcp: secure_seq: add back ports to TS offset. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <5da5662181ef8a251e3ba564903002c2e87de452 || >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <eae2f14ab2efccdb7480fae7d42c4b0116ef8805 || >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <46e5b0d7cf55821527adea471ffe52a5afbd9caf || >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <165573e41f2f66ef98940cf65f838b2cb575d9d1 || 443fac9f2618b93cbc5ab068dc594530236b3a23 || >=4.10.14 <4.11 | 5da5662181ef8a251e3ba564903002c2e87de452, eae2f14ab2efccdb7480fae7d42c4b0116ef8805, 46e5b0d7cf55821527adea471ffe52a5afbd9caf, 165573e41f2f66ef98940cf65f838b2cb575d9d1, 4.11 |
| Linux/Linuxgeneric | 4.11 | Not reported |
Published upstream
Mar 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: secure_seq: add back ports to TS offset This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-23247 records a Medium severity (CVSS 5.5) vulnerability in tcp: secure_seq: add back ports to TS offset. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <5da5662181ef8a251e3ba564903002c2e87de452 || >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <eae2f14ab2efccdb7480fae7d42c4b0116ef8805 || >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <46e5b0d7cf55821527adea471ffe52a5afbd9caf || >=28ee1b746f493b7c62347d714f58fbf4f70df4f0 <165573e41f2f66ef98940cf65f838b2cb575d9d1 || 443fac9f2618b93cbc5ab068dc594530236b3a23 || >=4.10.14 <4.11 | 5da5662181ef8a251e3ba564903002c2e87de452, eae2f14ab2efccdb7480fae7d42c4b0116ef8805, 46e5b0d7cf55821527adea471ffe52a5afbd9caf, 165573e41f2f66ef98940cf65f838b2cb575d9d1, 4.11 |
| Linux/Linuxgeneric | 4.11 | Not reported |
Published upstream
Mar 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: secure_seq: add back ports to TS offset This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset.
Quoted source text, attributed separately from HOL analysis.